CN111982963B - Thermal conductivity measurement method, system and device for precisely controlling and measuring medium surface temperature gradient - Google Patents

Abstract

The invention provides a thermal conductivity measurement method for accurately controlling and measuring the temperature gradient of the medium surface. The measured sample is placed at the center, and several temperature gradient control and measuring devices are used to surround the measured sample. The temperature The measuring end of the gradient control and metering device faces the surface of the sample to be tested, adjust the distance between each temperature gradient control and metering device and the sample to be tested, then start the temperature gradient control and metering device to measure, and read one or more samples of the tested sample. The local temperature gradient of different local regions of a surface can be used to obtain the precise thermal conductivity of the measured sample. This method accurately obtains the temperature gradient of each local area by measuring the temperature, heat flux density or a combination of multiple local positions on one or more surfaces, and solves the problem of inaccurate measurement of thermal conductivity of heterogeneous materials.

Description

Thermal conductivity measurement method, system and device for accurately controlling and measuring medium surface temperature gradient

technical field

The invention relates to the field of thermal conductivity testing, in particular to a thermal conductivity measurement method, system and device for accurately controlling and measuring the temperature gradient on the surface of a medium.

Background technique

Thermal conductivity, also known as thermal conductivity, thermal conductivity, etc., is a measure of the ability of a substance to conduct heat. In Fourier's law, it is equal to the heat transferred through the unit heat transfer surface in unit time under the unit temperature gradient, and the formula is expressed as:

k=-q/∇T;

In the formula, k is the thermal conductivity;

q is the heat flux;

∇T is the temperature gradient.

The definition of thermal conductivity is usually applicable to homogeneous materials and one-dimensional space. For heterogeneous materials and multi-dimensional spaces, the definition of temperature difference in a strict physical sense will become difficult, and the characterization of the thermal conductivity of the medium will also become complicated. Usually, the Apparent thermal conductivity, equivalent thermal conductivity, heat product dissipation thermal conductivity, etc.

The measurement of thermal conductivity is an important means to indicate the heat transfer performance of the medium. The existing thermal conductivity measurement methods include the steady-state method and the transient method. The principle of the test is to control and measure the temperature and heat flux on the surface of the medium. , and then the thermal conductivity is calculated by the heat conduction equation under different working conditions.

Existing test methods are more suitable for homogeneous materials, but for heterogeneous materials, there is no mandatory requirement to control and measure the temperature gradient at different local locations on all surfaces of the tested sample. For the same sample, the existing The thermal conductivity measured by the method may be different under different working conditions, resulting in low accuracy and stability of the measurement results.

In order to solve the above existing problems, people have been seeking an ideal technical solution.

Contents of the invention

The purpose of the present invention is to address the deficiencies of the prior art, thereby providing a thermal sensor with higher precision and better stability, which can solve the problem of inaccurate measurement of the thermal conductivity of heterogeneous materials and accurately control and measure the temperature gradient on the surface of the medium. Conductivity measurement method, system and device.

In order to achieve the above object, the technical solution adopted in the present invention is: a thermal conductivity measurement method for accurately controlling and measuring the temperature gradient of the medium surface, comprising the following steps:

Place the sample to be tested at the center, use several temperature gradient control and metering devices to surround the sample to be tested, the measuring end of the temperature gradient control and metering device is facing the surface of the sample to be tested, adjust each temperature gradient control and metering The distance between the device and the sample to be measured, and then start the temperature gradient control and metering device to measure, read the local temperature gradient of different local areas on one or more surfaces of the sample to be tested, and then obtain the precise thermal temperature of the sample to be tested Conductivity.

Based on the above, the temperature gradient control and metering device is a contact measuring device or a non-contact measuring device.

Based on the above, the temperature gradient control and metering device includes a housing and a first temperature compensator, a second temperature compensator, a first temperature sensor, a second temperature sensor, a control circuit board and a thermal sensor packaged inside the housing. A support plate with uniform conductivity, the support plate extends from the detection end of the shell to the tail end, the first temperature compensator and the first temperature sensor are fixed on the detection end of the support plate, the second temperature compensator and the first temperature sensor The second temperature sensor is fixed on the tail end of the support plate, the first temperature compensator, the second temperature compensator, the first temperature sensor and the second temperature sensor are all connected to the control circuit board, and the tail end of the shell is provided with a connection control board. The external interface of the circuit board.

A thermal conductivity measurement system for precisely controlling and measuring the temperature gradient on the surface of a medium, comprising a hollow support and a temperature gradient control and measurement device arranged on the hollow support, the detection end of the temperature gradient control and measurement device faces the hollow support At the center of and around the center of the hollow support, each temperature gradient control and metering device is connected to the central control system to collect and count the temperature gradient data on the surface of the measured sample.

Based on the above, the temperature gradient control and metering device is movably installed on the hollow support to adjust the penetration degree of the temperature gradient control and metering device.

Based on the above, the temperature gradient control and metering device is a contact measuring device or a non-contact measuring device.

Based on the above, the support is a closed or semi-closed support device.

Compared with the prior art, the present invention has outstanding substantive features and significant progress. Specifically, the present invention places the sample to be tested at the center, and arranges temperature gradient control and metering devices around the sample to be tested. Each temperature gradient control The measurement device and the measuring device respectively correspond to a local point of the tested sample to measure the temperature gradient, which is not limited to the specific shape of the tested item, and can accurately obtain the overall thermal conductivity of the tested sample, greatly improving the stability of the measurement and accuracy.

Description of drawings

Fig. 1 is a structural schematic diagram of a thermal conductivity measurement system for accurately controlling and measuring the temperature gradient of a medium surface in the present invention.

Fig. 2 is a structural schematic diagram of a thermal conductivity measurement system for accurately controlling and measuring the temperature gradient of a medium surface in another embodiment of the present invention.

Fig. 3 is a structural schematic diagram of the temperature gradient control and metering device in the present invention.

In the figure: 1. Hollow support; 2. Temperature gradient control and metering device; 3. Sample to be tested; 4. Shell; 5. First temperature compensator; 6. Second temperature compensator; 7. First temperature sensor; 8. Second temperature sensor; 9. Control circuit board; 10. Support board; 11. External interface.

Detailed ways

The technical solutions of the present invention will be described in further detail below through specific implementation methods.

As shown in Figure 1, one of the applications of the thermal conductivity measurement method for accurately controlling and measuring the temperature gradient of the medium surface, it specifically includes: a hollow support 1, a temperature gradient control and measuring device 2 arranged around the hollow support 1, The temperature gradient control and metering device 2 is installed on the housing 1, the shape of the hollow support 1 in this embodiment is a hollow cuboid, and the sample to be measured is fixed at the center of the hollow support 1, and the temperature gradient control The detection end of the measuring device 2 extends into the hollow position inside the hollow support 1, and each temperature gradient control and measuring device 2 is connected to the central control system to collect and analyze the temperature gradient data on the surface of the measured sample.

In order to adapt to the measured samples of different shapes, the temperature gradient control and metering device 2 is movably installed on the housing 1 to adjust the penetration degree of the temperature gradient control and metering device, and maintain a specific distance from the measured sample or Adhere to the surface of the sample to be tested.

The temperature gradient control and metering device 2 can be a contact measuring device, or a non-contact measuring device as shown in FIG. 2 . In this embodiment, a contact measuring device is used for illustration.

Specifically, as shown in FIG. 3 , the temperature gradient control and metering device includes a housing 4 and a first temperature compensator 5 , a second temperature compensator 6 , a first temperature sensor 7 , a second temperature compensator disposed inside the housing 4 Two temperature sensors 8, a control circuit board 9 and a support plate 10 with uniform thermal conductivity, the support plate 10 extends from the detection end of the casing 4 to the tail end, and the first temperature compensator 5 and the first temperature sensor 7 are fixed At the detection end of the support plate 10, the second temperature compensator 6 and the second temperature sensor 8 are fixed on the tail end of the support plate 10, the first temperature compensator 5, the second temperature compensator 6, the first temperature Both the sensor 7 and the second temperature sensor 8 are connected to the control circuit board 9, and the rear end of the housing 4 is provided with an external interface 11 connected to the control circuit board.

In other embodiments, the shape of the hollow support 1 can also be a hollow sphere or other shapes of closed or semi-closed hollow support devices, and its specific shape can be designed according to the shape of the sample to be tested.

working principle:

Place the tested sample 3 at the center of the hollow support 1, adjust the position of the tested sample 3 and the distance between the temperature gradient control and metering device 2 and the tested sample 3, then start the temperature gradient control and metering device 2 for measurement, read The local temperature gradient of different local regions on one or more surfaces of the tested sample 3 is obtained, and then the precise thermal conductivity of the tested sample is obtained.

When collecting temperature gradient data, the purpose of the first temperature compensator 5 and the second temperature compensator 6 is to keep the temperature of the two positions constant, and the function of the first temperature sensor 7 and the second temperature sensor 8 is to collect the temperature of the two positions. According to the temperature measured by the two temperature sensors, the distance between the two temperature measurement points and the cross-sectional area and thermal conductivity of the support plate, the temperature gradient and heat flux density can be calculated. The calculation process can be controlled by the circuit board The processor unit on the computer performs calculations, and the data obtained from the calculations are sent to the central control system through the external interface 11; the above data can also be directly sent to the central control system through the external interface for calculation, and finally the temperature gradient of each position of the entire measured sample is obtained , and then calculate the thermal conductivity based on the detailed data.

By adopting the technical solution provided by the invention, the problem of measuring the thermal conductivity of heterogeneous materials can be solved, and the accuracy and stability of the measurement can be improved.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: the present invention can still be Modifications to the specific implementation of the invention or equivalent replacement of some technical features; without departing from the spirit of the technical solution of the present invention, should be included in the scope of the technical solution claimed in the present invention.

Claims (6)

1. A thermal conductivity measurement method for precisely controlling and measuring the surface temperature gradient of a medium is characterized by comprising the following steps of: the method comprises the following steps:

placing a measured sample at a central position, and wrapping the measured sample by using a plurality of temperature gradient control and metering devices, wherein the measuring ends of the temperature gradient control and metering devices are opposite to the surface of the measured sample;

the temperature gradient control and metering device comprises a shell, a first temperature compensator, a second temperature compensator, a first temperature sensor, a second temperature sensor, a control circuit board and a supporting plate with uniform heat conductivity, wherein the first temperature compensator, the second temperature compensator, the first temperature sensor, the second temperature sensor, the control circuit board and the supporting plate are packaged in the shell;

and adjusting the distance between each temperature gradient control and metering device and the measured sample, then starting the temperature gradient control and metering device to measure, and reading local temperature gradients of different local areas of one or more surfaces of the measured sample, wherein the first temperature compensator and the second temperature compensator are used for keeping the temperatures of two positions constant, and the first temperature sensor and the second temperature sensor are used for collecting different temperatures of the two positions, so that the temperature gradient and the heat flux density are calculated according to the temperatures measured by the two temperature sensors, the distance between the two temperature measuring points and the cross section and the heat conductivity of the supporting plate, and further the accurate heat conductivity of the measured sample is obtained.

2. The method for measuring the thermal conductivity of the surface temperature gradient of the precisely controlled and metered medium according to claim 1, characterized in that: the temperature gradient control and metering device is a contact type measuring device or a non-contact type measuring device.

3. A thermal conductivity measurement system for precisely controlling and metering a medium surface temperature gradient, characterized by: the device comprises a hollow bracket and temperature gradient control and metering devices arranged on the hollow bracket, wherein the detection ends of the temperature gradient control and metering devices face to the center of the hollow bracket and surround the center of the hollow bracket, and each temperature gradient control and metering device is connected to a central control system to collect and count temperature gradient data of the surface of a measured sample; the temperature gradient control and metering device comprises a shell and a first temperature compensator, a second temperature compensator, a first temperature sensor, a second temperature sensor, a control circuit board and a supporting plate with uniform heat conductivity, wherein the first temperature compensator, the second temperature compensator, the first temperature sensor, the second temperature sensor, the control circuit board and the supporting plate are packaged in the shell, the supporting plate extends from the detection end of the shell to the tail end, the first temperature compensator and the first temperature sensor are fixed at the detection end of the supporting plate, the second temperature compensator and the second temperature sensor are fixed at the tail end of the supporting plate, the first temperature compensator, the second temperature compensator, the first temperature sensor and the second temperature sensor are connected with the control circuit board, and the tail end of the shell is provided with an external interface connected with the control circuit board.

4. A thermal conductivity measurement system for precisely controlling and metering the temperature gradient of a surface of a medium as set forth in claim 3, wherein: the temperature gradient control and metering device is movably arranged on the hollow bracket to adjust the extending degree of the temperature gradient control and metering device.

5. A thermal conductivity measurement system for precisely controlling and metering the temperature gradient of a surface of a medium according to claim 3 or 4, characterized in that: the temperature gradient control and metering device is a contact type measuring device or a non-contact type measuring device.

6. The thermal conductivity measurement system for precisely controlling and metering the temperature gradient of a surface of a medium according to claim 5, wherein: the support is a closed or semi-closed supporting device.

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